Perennial herb with one to three bulbs flowering stem 30 cm - 1 m tall, inflated below the middle Leaves: four to ten, arising from the base, elongate, 10 cm - 0.5 m long, 4 mm - 2 cm wide, cylindrical, hollow. Inflorescence: an upright, rounded umbel of up to 500 flowers raised on a single hollow stalk and subtended by two to three deciduous bracts. Flowers: on long stalks (much longer than flowers), pink to white with greenish midveins, 3 - 7 mm long, star- to bell-shaped, with six tepals that wither in fruit. Stamens six, exserted. Fruit: a short, three-lobed capsule. Bulbs: varying in size, usually less than twice as long as wide, somewhat rounded, and encased in a yellowish brown, red, or white coating. Easily distinguished from the stem.

Similar species: The cylindrical, hollow leaves and inflated stems of this species and Allium fistulosum help distinguish them from other Allium found in the Chicago Region. Allium fistulosum differs from A. cepa by having flower stalks shorter or equal to the flowers.

Flowering: May to August

Habitat and ecology: Introduced from Asia. An occasional escape from cultivation or arising from food waste. Has been found along railroad tracks and in waste ground.

Occurence in the Chicago region: non-native

Notes: Widely cultivated in North America, Europe, and Asia. There are numerous cultivars derived from this species.